Depth charge direction indicator



June l, 1954 R DELSASSO 2,680,238

DEPTH CHARGE DIRECTION INDICATOR Filed July l1, 1946 2 Sheets-Sheet l a G l/ lab C T41 35g 4o L 38 as 55 I( l F G. 3 INVENTOR. LEO P. DELSASSO BY @4Q/74,0

Attorney June 1, 1954 l.. P. DELsAsso DEPTH CHARGE DIRECTION INDICATOR 2 Sheets-Sheet 2 Filed July l1, 194

I l l l l \I l I n mm INVENTOR. LEO P. DELSASSO Attorney' Patented June 1, 1954 UNITED STATES TENT' OFFICE 9 Claims, (Cl. 340-6) (Granted under Title 35, U. S. Code (1952),

sec. 266) 1 2 This inventionrelates to explosion direction together with a schematic showing of the selector.

indicators and more particularly to devices for recording the direction of depth charge explosions.

A recording type of depth charge direction indicator is useful in selecting the best escape course for a submarine to use while it is being subjected to an attack. A simple device capable o-irecording the general direction of as many as five depth charge explosionsl before it requires resetting has been found necessary. The device should be capable of recording another set of explosions upon pressing a reset button.

An object of this invention is to provide cornpact and rugged equipment which will indicate l.

the direction of a depth charge explosion.

Another object is to providev a recorder which is positive in action and is capable of observing repeated explosions.

A further object is to provide a recorder which will give a quick visual indication of a plurality of depth charge explosions.

The invention also residesin certain novelfeatures of electrical andl mechanical component structures and arrangements which facilitate the carrying out of the foregoing objects and which contribute both to the simplicity of the device andto the reliability of operation as well as to the ease andexpeditious manner of determining the directionof an explosion.

These results are obtained in the present device by an arrangement of four contact hydrophones located at equal distances on the circumference of a circle surrounding the conning tower of a submarine. A relay advanced switch is used.V

to connect these hydrophones successively to groups of' glow tubes arranged in series on a cross whose arms are related in position to the hydrophones.

Resistance circuits are provided to prevent more than one glow tube in each connected group from being ignited by a single explosion. An electronic delay device is employed toV prevent the selector relay from being advanced more than once by a single explosion.

Other objects andi advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings in which:

Figure 1 is a plan view of the glow tube arrangement.

Figure 2 is a diagram of the electrical circuits from the hydrophones to the glow tubes.

Figure- 3` is a diagram of the electronic means which are. used for advancing the selector relay,.

relay.

While the invention is susceptible of various modications and alternative arrangeinents,l I have shown in the drawing and will herein de scribe in detail the preferred embodiments. It is to be understood, however, that I do not intend to limit the invention by such disclosure for I aim to cover all modifications and alternative a1:- rangenients falling within the spirit and scope of the invention as donned in the appended claims.

Figure 1 shows a cross-like arrangement lil; on which are mounted neon glow tubes. The four spokes o the cross are the 00 spoke, 90 spoke, etc. A series of tubes l la through i ie is mounted in succession outwardly on the 0 spoke or the cross. The tubes are connected to hydrophone il, which is disposed on the deck of the submarine at a relative bearing of about 045. Tubes [2a through (2e are similarly arranged onthe 90 spoke and connected to hydrophone- I2 which is located at approximately 135 relative bearing on the submarine. Tubes 13a through |73@ are located on the 180 spoke and connected to hy d-rophone i3 which is at a relative bearing of 235. on the submarine. Tubes Ilia through (4e are locatedr on the 270 spoke and are connected to hydrophone lll which is located at a relative bearing of about 315.

Figure 2 shows the circuit for connecting each of the four hydrophones to one of a group of the neon glow tubes and for actuating one tube o each group for each explosion. In this circuit the contact type hydrophones il through Hl are each connected on one side to ground and on the other side to switches it which lead to resistances 2| and 22 which are in series with each of the hydrophones. The connection between resistances 2| and 22 in each case is further connected. to one oi a set of selector switches 23. These four switches areV connected in gang fashion., and each is arranged to contact consecutively a similar point in one of four similar seriesV each containing ve switch points 23a through 23e. The four contacts 23e are connected to the connectionpoints of series connected resistors 2d and 2.3 in unit 25e. ContactsV 23a. through 23d are connected in like manner to units 26e through 25d.

Glow tubes ll'e through` l-e are connected to resistor 2l' which is grounded on the other side. Resistors 25 are similarly grounded'. The other connections of thev tubes go to variable contactors 2.8 which act on variable resistors 2t. Resistors- 24 are connected to a source 29 of positive potential through a switch 30, as are also the resistors 2|. The negative side of the source 29 is grounded. rlhe positive line from source 29 is connected to resistors similar to 24 in each of the units 26a through 26d. A line also runs from resistors 25 to similar resistors in units Zta through 26d. Resistor 2 is connected to ground as are similar resistors in unit 26a through 25d. The connections between resistors 22 and switches i3 are connected to resistors 3l which are connected to the trip circuit. Ratchet wheel 32 is connected to the gang switches 23.

Figure 3 shows the trip circuit for actuating the selector ratchet wheel 32. The anodes of two grid controlled gas filled thermionic tubes Bill and 35 are connected together. rhe cathode of tube 34 is connected through series resistors 36, 3'5 and 3B to ground. The cathode of tube 35 is connected to ground. Series connected resistor 3Q and condenser @il are connected between the f cathodes of the two tubes through a variable contactor di which connects resistor 39 to variable resistor 37. The heaters for tubes 34 and 35 are connected to a suitable source of potential 35A. The negative side of this source is connected to the negative side of a source of anode potential 35B. The screen grids of tubes 34 and 35 are connected to a source 35C of positive grid potential. The control grid of tube 34 is connected to the lead from the resistors 3l which are connected to the hydrophones. A resistor 32 is also connected to this grid and to ground. The control grid of tube 35 is connected between resistor 3S and condenser 4B.

Solenoid 4arm All is pivotally mounted above soienoid d5. Pivoted pawl 4l is mounted at the outer end of arm i4 and engages the teeth 48 of ratchet wheel 32. Lug 5i engages switch 52. A spring 53 tends to rotate wheel 32 in a counterclockwise direction. Reset lever 55 is actuated by button 56. One end of the solenoid is connected through switch 52 to the tube anodes and the other end to the positive side of source 35B. Selector switch 5l is used in adjustment.

In operation, the four contact hydrophones are located at equal distances on the circumference of a circle surrounding the conning tower of a submarine. These hydrophones are connected to the four series of ve small neon glow lamps which provide a recording apparatus in the form of a cross to indicate the direction in which the explosion takes place. The hydrophone connections go through appropriate watertight fittings to the recording apparatus which is located in the interior of the vessel. Hydrophone il can be successively connected by solenoid operated selector switch 23 to any one of the glow lamps I la through He on the 0 spoke. The switch 23 is actuated by the electronic trip circuit or by manual switch 51. Hydrophones i2 through lli are similarly connected to lamps l2a through 12e, |30. through 13e and ida. through Me..

The apparatus is actuated by the steep initial pressure pulse produced by the explosion of a depth charge. This pulse aiects the four contact hydrophones in succession. opening nrst the contact of the hydrophone closest to the location of the explosion. Due to the circuits used between the hydrophones and the glow lamps, only one glow lamp will be ignited by this opening of the hydrophone contact.

As is known a glow lamp has two critical voltages, one at which a glow just sets in and another at which the glow extinguishes. While any suitable voltage range may be used in this device, a satisfactory lamp is one having the following characteristics:

Upper critical voltage (striking potential) Eu=78 volts (average value) Maximum glow tube current I=748 microamps.

Lower critical voltage E1=60 volts (average value).

Mean voltage (78+60)/2Em=69 volts.

Mean current Im=400 microamps.

Suitable resistor values are as follows:

Resistor Ei--lOOO ohms. Resistor 22:2(),000 ohms. Resistor 2=25,000 ohms. Resistor 25:50,()00 ohms. Resistor 3i=30,000 ohms.

The potential source 29 should be about 90 volts for this type of lamp. The variable resistors 2e are set to provide a potential which is somewhat below the striking potential when the contact hydrophones are closed due to current flowing through resistors 2i and 22.

The a glow lamps are connected to the hydrophones in the initial position. When an explosion in the nrst quadrant opens the contacts of hydrophone il, the current ilow through resisters 2i and Z2 is stopped. This raises the potential on the glow tube ilaf in the 0 spoke from 69 to 84 volts causing it to ignite. Upon closing the hydrophone contact, the potential is reduced to a value of about 69 volts which is sufcient to keep the glow lamp -i la ignited.

As hydrophones l2 through i4 in this particu-v lar example will also be affected by the explosion, although somewhat later than hydrophone Il, glow lamps 12a through fia would also be ignited if the circuits containing lamps l la through lila were not interconnected and suitablyy adjusted. Because oi this connection, when a glow discharge ignites lamp lia, it will also cause a current fiow of about 400 microamps through resistor 2l which reduces the potential across the remaining tubes to 55 volts. When hydrophone i2 is opened the potential across tube 12a is increased to 69 volts which is insufficient to igniteA the tube. Hence, only the glow tube on the 0 spoke can be ignited when an explosion takes place in the quadrant of hydrophone Il.

After an explosion the electronic trip circuit advances the selector switches 23 to connect the hydrophones to the next group of glow lamps to record the next explosion. An underwater explosion causes a report due to a sudden expansion, then a report due to a sudden contraction, and often a series of such reports. Accordingly, provision has to be made for recording only the rst report; otherwise several glow lamps will ignite instead of only one for each explosion. This is done by means 01"' the thyratron circuit shown in Figure 3. When a sound pulse from a depth charge explosion A actuates hvdrophone,4 Il, the potential of the control grid of tube 34 is changed sufficiently to cause the tube to strike. This is due to opening a circuit to ground through the hydrophone H. When the tube strikes, a small current is started through resistances 3S,y 3l and 38 setting up a potential difference across resistance 39 and condenser lill. This causes condenser 40 to charge slowly and after a few seconds to alter suiciently the potential on the control grid of tube 35 to cause it to strike. The combined plate current of both tubes is sufcient to activate solenoid which pulls down arm M- and' advances the selector switch ratchet wheel 32. to the next position. Due to lug 5I, the plate circuit current is broken and both tubes are extinguished. r.The time delay provided by this circuit avoids repeated operation of the device from a single depth charge.

When an explosion has been recorded on one of the "c lamps, the gang selector switches 23 connect the tubes to the hydrophones due tothe advancing of the relay ratchet wheel` 32 by means of the electronic circuit. A second explosion will' ignite the appropriate "b" tube and the selector relay will move one notch forward to connect' the hydrophones to the c tubes. After Ive explosions have been recorded in the device illustrated, the reset button 56 can be pushed so' that the ratchet wheelv will be driven back to its original position by spring 53, thus switching the apparatus so that the a tubes are again connected to the hydrophones. Switch 30 should. also be opened at this time in order to extinguish all glow lamps which have been ignited by the previous explosions. If desired this switch may be hooked to reset button 5t in order that pushing this button will also open switch 30. As shown, successive explosions B, C, D and E- light lamps i2b, lic, Idol and iSe. The gang switch is shown in the "e position in Figure 2.

Switch 5l is used when adjusting to obtain the correct potential on the glow tubes and is manually operated. In carrying out such adiustment, contactcrs 23 are set on resistors 2li at the point of minimum potential. Switch 30 is closed but the heater current source is disconnected sothat actuation `can be made only by the manual selector switch 5l. With the hydrophone H connected in the circuit as is always the case for the normal condition of the hydrophone, contactor 28 for tube ila is gradually brought toward a position of maximum potential until the "l tube ignites. This position is marked. The contactor is again set at minimum potential and switch 30 is opened and then closed again. Opening the switch stops the glow discharge of tube Ila land closing the switch causes a potential across the glow tube which is not suiiicient to initiate a glow discharge. With the switch I8 in the hydrophone l i circuit open, the potential is again raised until a glow discharge appears in tube lla. This position is also marked. The resistance is then adjusted to a point midway between the two marks. This is the correct position for operation of tube lla on the 0 spoke. In order to adjust to the correct position of the contacter for tube l lb, it is necessary to close the manual selector switch el so that tube l l b is connected into the circuit, this switch normally being open. Hereafter, the adjustment is the same as described above. The correct settings of contactors 28 are similarly found for glow lamps lic, Ild and He. After this is done, the reset button 56 is pushed and the potentials for the 90 lamps are adjusted as above. The 180 and 270 lamps are similarly adjusted. The switches I8 are normally closed, being used only to open the hydrophone circuits in testing.

The invention Idescribed herein may be used by or for the Government of the United States for governmental purposes without the payment to me of any royalties thereon or therefor.

What is claimed is:

1. In an explosion direction indicator, a plurality of energy pick-ups arranged in a pattern, a plurality of signals associated with each of these pick ups arranged in a related pattern, and

switching means for connecting each pick up successively with a different one of its associated signals after each explosion, the pick-up nearest the explosion responding and actuating its associated signal to indicate the direction of the explosion.

2; An impulse direction indicator comprising a plurality ofv energy pick-ups arrangedin a symmetrical pattern, a plurality of signals arrangedY in a related pattern, an equal portion of saidI plurality of signals being associated with each energy pick up, and switching means for successively connecting each of the pick ups to a different one of its associated signals after each impulse' is received, the pick-up nearest the impulse responding to it and actuating its associated signal to indicate the direction of the impulse.

3'. A sound source direction indicator comprising a plurality of contact type hydrophones arranged in a pattern, a plurality or" visual signals associated with each of said hydrophones and adapted to be energized thereby, a current source, andn means for connecting each hydrophone successively with a different one of its associated visual signals each time a hydrophone is energized, the hydrophones and signals being connectedI in parallel across the source, whereby the opening of one of the contact hydrophones increases the potential on its associated signal to cause it to indicate.

4. In an explosion `direction indicator, the lcombination of a plurality of energy responsive means arranged in a symmetrical pattern, a plurality or indicators associated with each energy responsive'- means, said indicators being arranged in groups, the indicators in each of said groups being responsive to one of said energy responsive means, and means for successively connecting each of the energy responsive means to a different one of the indicators in its associated group after each explosion, said last mentioned means being activated by any of said hydrophones, so that an explosion affecting the nearest energy responsive means thereby activates the iirst indicator in the associated group to in-dicate the direction of the explosion, and a subsequent explosion similarly activates the next indicator in the group related to the direction of the subsequent explosion.

5. An explosion direction indicator comprising a plurality of energy responsive devices arranged in a symmetrical pattern, a plurality of indicators associated with each energy responsive device, said indicators being arranged in groups, the indicators in each of said groups being responsive to one of said energy responsive devices, a selector relay for successively connecting each of the energy responsive devices to one of the indicators in its associated group, and a relay operating means connected to the energy responsive devices to advance the selector relay after each explosion, so that an explosion aiecting the nearest energy responsive device activates the first indicator in the associated group, and subsequent explosions similarly activate the next indicator in sequence in the group related to the direction of the explosion.

6. Apparatus for determining the direction of source of wave energy comprising a plurality of Wave energy detectors arranged in a symmetrical pattern, a plurality of indicators associated with each wave energy detector, said indicators being arranged in groups, the indicators in each of said groups being responsive to one of said Wave energy detectors, a selector relay for successively connecting each of the wave energy detectors to the indicators in its associated group in sequence, a relay operating means connected to the wave energy detectors to advance the selector relay on receipt of each wave, and a time delay circuit to prevent undesired relay advances, whereby a wave of energy affects the nearest wave energy detector to activate the first indicator in the group associated with that wave detector, and subsequent waves similarly activate the next indicators in sequence, in the groups associated with the subsequently energized detectors.

7. In a device for determining the direction of a wave source comprising a plurality of wave detecting means arranged in a symmetrical pattern, a plurality of indicating means associated with each wave detecting means, said indicating means being arranged in groups, the indicators in each of said groups being responsive to one of said wave detecting means. a selector relay for sequentially connecting each of the wave detecting means to the indicating means in its associated group, a relay operating circuit connected to the wave detecting means to advance the selector relay on receipt of each wave and a time delay circuit to prevent undesired relay advances, whereby successive waves aiect the nearest wave detecting means to sequentially activate the indicating means in the group associated with each energized Wave detector, and a resetting device to deactivate the indicating means and return the relay to its starting position.

8. The apparatus recited in claim 7 in which there is a manually operated switch to advance the selector switch for initial adjustment of the indicating means.

9. An explosion direction indicator comprising four hydrophones each located at the midpoint of one quadrant of a circle, four groups of signal lamps forming lines at 90 intervals related in position to the quadrants, each quadrant having one of said groups associated therewith to indicate explosions occurring therein, a stepping switch connecting each hydroplione with the particular group of signal lamps associated with the quadrant in which the hydrophone is located, said. stepping switch being energizable by any of said hydrophones, said stepping switch connecting each hydrophone successively to a different signal lamp in its group after each explosion, a source of potential for energizing said signal lamps, a resistance network connected between said potential and said lamps to permit the illumination of only one lamp in a group, a stepping switch operating circuit connected to the hydropliones, a time delay circuit connected to the stepping switch operating circuit to prevent undesired switch advances, and a reset device for extinguishing the lamps and returning the stepping switch to its starting position.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Re. 22,611 Edgerton Mar. 6, 1945 2,007,211 Nicolson July 9, 1935 2,104,142 Swart Jan. 4, 1938 2,166,287 Swart Jan. 25, 1938 2,206,827 Prince July 2, 1940 2,396,280 Miller Mar. 12, 1946 2,398,411 Cool; Apr. 16, 1946 2,427,569 Nicolson Sept. 16, 1947 

